Recording Mode
Live first-principles thermal model

Physical Model Simulation: Electric Water Heater

Energy input → thermal mass → heat loss → temperature change

Digital twin boiler

HEATER ON
Electric power input
Outlet 0%
Inlet closed
22.0 °C
target 60 °C
INLET CLOSED
Current22.0 °C
Target60 °C
Ambient20 °C
Power draw2000 W
Energy0 Wh
Outlet0%
Level100%
Inlet valveClosed

Water temperature

22.0 °C

Electric power

2000 W

What the physical model calculates

  • Electrical power heats the water
  • Thermal mass slows down temperature changes
  • Heat loss increases with the temperature difference to ambient
  • Hot water draw-off is replaced by colder inlet water
  • The thermostat uses hysteresis to switch the heater on and off
  • Simplified assumptions can create model bias
dT/dt = (P_eff - Q_loss + Q_flow) / (m · c)
Q_flow = m_dot · c · (T_inlet - T_water)

Key message

Physical models are interpretable, robust, and trusted — but only as accurate as their assumptions.

Low variance. Potentially high bias.
Simulation self-check: running

Physical models are interpretable and robust — but simplified assumptions can create bias.